How did you get into electronics/engineering and when did you start?

I was originally attending the University of Tennessee and studying biology, of all things. In my junior year, it became clear to me that in order to do anything that I really wanted to do in biology, I was going to need a PhD. I wasn’t sure if I was genuinely interested enough in the subject to devote the time needed to achieve that, so I dropped out my junior year and enlisted in the Air Force. I decided that I wanted to travel, see the world, and do interesting things. I really wanted to live overseas for a while. Well, I never got the opportunity to live overseas; I was stationed state-side the whole time. But I was trained in electronics in the Air Force, and that is how I originally got into this field. When I got discharged, I enrolled at the University of New Mexico to finish my bachelor’s degree. I had been stationed in Denver, Colorado and loved the area, and wanted to go to the University of Colorado. But of course anywhere I went would be out of state, and the University of Colorado was too expensive. New Mexico, however, a bordering state, was within the price range I could afford with the GI bill.

I completed my bachelor’s at the University of New Mexico and went on from there to work at Teledyne Camera Systems in Acadia, California. I worked on analog electronics for a digital film conversion system, to store Hollywood films in a digital format. At the time they had all of the movies on film, and after time the film degrades in the vaults so we had come up with an idea of how to digitize it all. I worked on doing that for a while and decided that California was way too expensive at the time, given my salary. I was married and my husband was having a hard time finding a job. We decided to move back to New Mexico where I got a job offer at Sperry, which later became Honeywell Aerospace and Marine Systems. I spent about six years there and decided that I wanted to go on for my master’s degree.

I went back to the University of Tennessee for my master’s, and when I graduated we were in a recession. Jobs weren’t plentiful, but I was able to get a position at Oak Ridge National Laboratory, working in electronics. I worked there for several years and then left to go work for a small start-up design company doing semiconductor design. The company was sold to Flextronics, at which time I left and returned to Oak Ridge National Labs and have been here ever since, now nearing 20 years.

What type of work do you do at Oak Ridge National Laboratory?

For the past seven years I have been in hybrid electric vehicle technologies. We are the Department of Energy’s (DOE) premier power electronics and electric machines laboratory. We do novel, next generation designs for the electronics and the motors for hybrid, electric, and fuel cell vehicles.

It is a national laboratory; is it government-related research?

We get the majority of our funding from the Department of Energy. With the funding we are tasked with looking at far reaching, long term, new technologies that the OEMs or suppliers don’t have the resources or luxury to look at. They are all tasked with, “What do we do to get to the next model?” We are looking at technologies for ten years down the line.

Can you tell us a little bit about the research you are doing?

Like I said, the majority of our funding comes from the Department of Energy, but we also work with companies directly. We do a lot of work with the automotive OEMs and Tier 1 and 2 suppliers. Most of that work is on a proprietary level. The work that we do for the Department of Energy is all open to the public, since is it funded by tax dollars.

Right now, I think the most exciting project we are working on is one for wireless power transfer for charging the large battery packs in electric and plugin hybrid vehicles. We got into this several years ago. It is sort of the buzz word now and everyone appears to be jumping on the bandwagon, but ORNL started back when very few people had ever even thought of it for vehicular applications. In the future, I feel that all electric and plugin hybrid cars will have this technology in them.

With this technology, there is a receiving antenna on the underside of your car. You will also have a transmitting antenna in your garage that is built into the concrete floor or part of a mat you can throw down on the floor. When you park your car in the garage, you will not have to plug it in to charge the battery; it will receive its charge from the transfer of power from the garage floor up into the car.

Oak Ridge is now taking the next step forward, which is probably a technology about 10 years down the line, where we are going to be embedding these coils in roadways. The DOE’s mission is to find ways to eliminate our dependency on foreign oil. To do that, we want to move toward the electrification of vehicles. We are working toward embedding charging coils in the road, and similar to a carpool lane, you will have a charging lane. As you drive your electric vehicle, you will be picking up a charge. You can enter the freeway with not quite a full charge, you will pick up charge as you drive down the lane, and you can exit with a fully charged battery. The car’s communications system will control whether the battery will receive a charge and will even be able to talk to your utility company to bill you for the electricity used. This will allow the downsizing of battery packs, making the cars lighter and more efficient, leading to cost reductions of these vehicles, accelerating them into the marketplace.

What type of system is being used for this technology?

It is a resonant system, which has inherent voltage isolation for safety. Since it operates at resonance, it is not going to draw power unless there is a matching antenna above the transmitting antenna. We are currently operating our system at about 20 kilohertz, though other companies are utilizing other frequencies. At Oak Ridge we are transmitting about five kilowatts of power across a 250-300 millimeter distance gap between the two antennas with fairly high efficiencies.

Believe it or not, this technology is moving so fast, there is now a standards committee that has been formed to establish wireless charging standards. I believe the targeted efficiency is 90 percent, from the wall to the battery.

Have you been building prototypes?

Yes, we have. We have a moving prototype demonstrator unit and we have been doing a lot of work on the antenna design this past year. Our demonstration unit is used primarily for testing our different design options. We are moving forward with plans to build our first ‘in motion’ charging prototype

Do you test the difference between the moving and stationary antennas?

Yes, our demonstration prototype has been fabricated so we can adjust alignment in three dimensions. One antenna is on a motorized track and we can test field coupling between the two antennas as a function of the antennas’ alignment.

When you are moving one antenna over another one, our demonstration test bed moves fairly slow. The station we have set up right now would represent stationary charging or what we call opportunity charging. Opportunity charging would be at red lights, stop signs, bus stops—any spot where you would momentarily stop your vehicle. While you are sitting there, waiting on traffic, your car would pick up a charge.

Ideally, one of the first demos that we wanted to do was testing the system with shuttles at airports, which is a perfect fit for this technology. The vehicles routes are well-defined as well as where they will park. The buses or shuttles can charge their batteries while waiting for customers to load, drive the customers to their destination, and then sit and wait for additional customers while getting another charge.

What size of an antenna is being used?

The first one we began working on takes up most of the undercarriage of the car. It is about 36” x 40”. One problem is, where you build the matching antenna in your garage, or in a parking garage, will depend on knowing where the position of the antenna is in your car. The location and size of the antenna in the vehicle will need to be standardized, so whether they are pulling forward or backing into the parking space, they can position it correctly for maximum coupling. The goal is to develop an antenna that is about a 10” x 10” square that will be located under a car’s trunk. We are hoping to move to that, but right now the demo is just to test the science, location, separations, and size.

How much does the body of the vehicle impact the tuning of the antenna?

There are shielding and EMI issues that are part of the ongoing work.

What is your primary role in this project?

I am the Director of Vehicle Electrification Partnerships at Oak Ridge National Laboratories. I oversee technical aspects of projects.

Are there any other interesting projects that Oak Ridge is working on?

One big issue is that most of the motors in hybrid vehicles have been using rare earth magnet materials. These motors have internal or surface magnets. The biggest supplier of these materials is China. We get about 97 percent from them. There is a big push to change this because China is so quickly becoming so technology driven that they are starting to use more of these materials in-house. The cost of the materials has doubled in the past year. The automobile industry is all about cost. We have new projects going on, and one is learning how to develop motor technologies that do not use these rare earth magnets. Right now these rare earth machines have the highest power density of any motor utilized for hybrids. The trick is to develop motors that do not use the rare earth magnets but have the speed and torque characteristics of rare earth machines, as well as their efficiency and power density. We have a number of projects going on in this area.

We are also looking at alternative permanent magnet motor technologies—ones that use different types of magnets, not composed of rare earth materials. We are also looking at electromagnets to generate the electric fields. We are re-examining motor technologies that have been used for other applications, dismissed by OEMs because the rare earth permanent magnet machines perform so well. We are investigating ways to make these motors more effective. One technology is induction machines. They are the workhorse of the industry but they are bigger and heavier than the rare earth motors. There may be a case that can be made for induction machines in all electric vehicles. We think that we have a few ideas to make the induction motors more efficient and we are pursuing this research area.

How hard is it for private industry to work with you on developing new technologies?

We make it pretty easy for private industry to work with us. We have meetings twice a year and a review in Washington where industry people can come in. If they see technology that they are interested in and want to pursue, we offer licensing agreements so that we can promote getting these things out into the industry. That is ultimately our goal, to get technologies we develop out into commercial use.

What challenges do you foresee in your industry?

The market acceptance due to unproven reliability and high cost of electric vehicles.